1. Field of the Invention
The present invention relates to a lens-equipped light-emitting diode device which extracts light from a light-emitting diode through a lens and a method of manufacturing the same, and particularly to a lens-equipped light-emitting diode device which is excellent for light extraction efficiency and reliability and whose production cost can be reduced.
2. Description of the Related Art
FIG. 13 is a longitudinal sectional view showing a conventional lens-equipped light-emitting diode device 100. In the lens-equipped light-emitting diode device 100, a light-emitting diode element 102 is mounted through a die mounting material (not shown) on a lead frame 101 in which an electrode is formed, and an electrode of the light-emitting diode element 102 and an electrode exposed outside the lead frame are connected by a bonding wire 103.
A sealing portion 104 made of resin is formed around the light-emitting diode element 102, and an outer peripheral unit 105 is formed outside the lead frame 101 and light-emitting diode element 102 using a white thermoplastic resin. A lens 106 is attached to upwardly collect light emitted from the light-emitting diode element, and the lens 106 is made of a transparent resin produced in a different process. In FIG. 13, the number 107 designates a bonding agent.
Generally a transparent resin is used as the sealing portion 104. Recently, a white light-emitting diode device is proceeding toward the practical use in illumination. In this case, frequently a fluorescent material for converting blue or UV light emitted from the light-emitting diode element is mixed into the transparent resin.
In the conventional lens-equipped light-emitting diode device, the lens 106 produced in the different process is attached to the outer peripheral unit 105 by bonding or fitting. A method of casting a thermosetting resin into the outer peripheral unit 105 is also adopted (for example, see Jpn. Pat. Appln. KOKAI Publication No. 2004-343059).
In the conventional lens-equipped light-emitting diode device, there are the following problems. In the case where the lens 106 is attached to the outer peripheral unit 105 by bonding or fitting, sometimes a micro-gap is generated between the sealing portion 104 and lens 106, which decreases light extraction efficiency. There is also generated the problem that mechanical strength or a heat-resistant property is degraded due to poor adhesion between the lens 106 and the outer peripheral unit 105.
On the other hand, in a production process, the following factors become an obstacle for reducing assembly cost. That is, an assembly process of attaching the lens 106 to the outer peripheral unit 105 is required, and an optical axis adjustment process is required to accurately attaching the lens 106 to the outer peripheral unit 105. In the case where the lens 106 is formed by casting, only the thermosetting resin is used. However, generally a long-time curing process is required for the casting, so that the cost reduction also becomes the problem in the casting.